From economical point of view, most renewable energy sources currently show competitive economical properties in comparison with conventional sources, especially if their true lifecycle costs are taken into consideration. This multidisciplinary book focuses on the evaluation of the techno-economic performances of photovoltaic and wind energy systems. Various modes of operation are considered. These modes include grid-connected and off-grid applications. In addition, various types of loads are considered, including non-deferrable and deferrable loads. Viable techno-economic performance and optimization of Renewable Energy Systems (RESs) for economic performance maximization is among the main objectives of this reference. The book is written for students, researchers, and relevant specialists. Nineteen authors contributed to this book. They are from seven countries; Egypt, Turkey, Croatia, Mexico, Germany, Algeria, and Norway. The authors are: M. EL-Shimy (ed.), H. Balcioglu, K. Soyer, M. A. Abdelraheem, M. Said, M. Noor, T. Abdo, B. Đurin, J.G. Vargas-Hernández, A.C. Rangel, L. Nađ, K. Pallagst, P. Hammer, N. Bailek, K. Bouchouicha, A. Slimani, N. Aoun, A. Razagui, and N. Veggeland.